Costco Wholesale · Domain Security

Costco Domain Security

Domain security

Domain security posture for Costco Wholesale, probed live across 1 host(s) and 1 registrable domain(s). 1 host(s) serve HTTPS (up to TLSv1.3); 1 advertise HSTS. Email/DNS controls: DNSSEC absent, SPF present, DMARC present (p=reject).

B2BBig-BoxE-commerceEDIFortune 500GroceryMembershipPharmacyRetailSupplier PortalTravelWarehouse ClubWholesale

Transport & Host Security

www.costco.com
HTTPS: yes · TLS: TLSv1.3 · HSTS: yes · cert expires: Sep 6 23:59:59 2026 GMT

Domain (DNS/Email) Security

costco.com
DNSSEC: no · SPF: yes · DMARC: yes (p=reject) · CAA: yes

Source

Domain Security

costco-domain-security.yml Raw ↑ 
generated: '2026-07-11'
method: probed
source: live DNS/TLS/HTTP probes of apis.yml + OpenAPI hosts
hosts:
- host: www.costco.com
  https: true
  tls_version: TLSv1.3
  cert_expires: Sep  6 23:59:59 2026 GMT
  hsts: true
  hsts_max_age: 31536000
domains:
- domain: costco.com
  dnssec: false
  caa:
  - 128 issue "certainly.com"
  - 128 issue "digicert.com"
  spf: true
  dmarc: true
  dmarc_policy: reject